JP2001029165A - Tilting seat chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair equipped with an adjusting means having an elastic means and especially simple, strong, and miniaturized structure. SOLUTION: This tilting seat chair is provided with a foundation structure 16 for supporting a crossing inclined shaft, a seat supporting structure 14 tiltably fitted to the circumference of a crossing inclined shaft 24, an elastic means 32 resistible to the seat tilting motion, and an adjusting means 42 for changing the resisting force to the elastic means 32. The elastic means 32 has a torsion bar 32 for connecting the seat supporting structure 14 to the foundation structure 16 in such a way that it is inclined around the crossing inclined shaft. The torsion bar 32 comprises at least one of first parts turnably connected to the seat supporting structure 14, and at least one of second parts connected to the foundation structure 16 by means of an adjusting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention provides:-a basic structure for supporting a transverse tilting axis;-a seat supporting structure provided so as to be tiltable around the transverse tilting axis;-elastic means capable of resisting the seat tilting operation; The present invention relates to a chair of the type provided with a tilting seat, which has adjusting means for changing the force opposing the elastic means.

It is an object of the present invention to provide a chair provided with a tilting seat of the type described above, provided with elastic means and adjusting means having a particularly simple or robust and compact construction. It is a further object of the present invention to provide a device for adjusting the elastic means against skewing of the seat, which does not require a large operating force.

According to the invention, these objects are achieved by a tilting sheet having the features that constitute the subject of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail hereinafter with reference to the accompanying drawings, given by way of non-limiting example only.

FIG. 1 illustrates a chair provided with a seat 10 and a backrest 12. The seat 10 is of a type known per se, which is mounted so as to be tiltable about a transverse axis relative to a base structure 16 mounted on a height-adjustable central support 18. 14 attached.

Referring to FIG. 2, in view of its construction, the seat support structure 14 includes two longitudinal members 20 of a curved sheet that are transversely spaced and connected together by a back plate 22. The base structure 16 is formed of a substantially box-shaped body having a transverse tilt axis 24 around which the seat support structure 14 is tiltably mounted. A pair of tubular members 26 are attached to the longitudinal members 20 and the oblique axes 24
And coaxially arranged.

In FIG. 2, reference numeral 28 denotes a support structure for a backrest. The support structure is tiltably mounted on the base structure 16 around a second transverse tilting axis 30 parallel to the tilting axis 24 and is set at a slight distance from the latter towards the back of the chair. . The backrest support structure 28 is connected to the seat support structure 14 by a pair of connecting bars (not shown) so that the tilting movement of the seat and the backrest is synchronized. Mechanisms for securing the seat and back in a plurality of operating positions are described in detail in similar patent applications by the same applicant.

Referring to FIGS. 4, 5 and 6, the oblique axis 24 of the seat support structure 14 includes a torsion bar 32 extending coaxially with the axis 24. In view of its construction, the torsion bar 32 includes a plurality of elongated rods 34 having a flat rectangular cross section. A number of rods 34 are stacked on one another and attached together in such a way as to form a transversely extending rectangular cross-section bar that is slightly larger than the distance between the longitudinal members 20 of the seat support structure 14. As can be seen particularly in FIG. 6, the end portions 32 a of the torsion bar 32 project laterally outside the two longitudinal members 20. End portion 32 of torsion bar 32
a is a tubular member 2 forming part of the seat support structure 14;
6 is attached. This attachment is achieved, for example, by a pair of washers 35 welded to the tubular member 26, having a square hole engaged by the end portion 32a. The transverse pin 36 prevents the torsion bar 32 from moving in the axial direction. A part of the torsion bar 32 projecting to the side is covered by the corresponding cap 38.

The central portion 32b of the torsion bar 32
It is rotatably connected to the lever 40. In the example illustrated in FIGS. 4 and 5, the rotatable connection between the lever 40 and the central portion 32b
This is achieved by the fact that the lever 40 has a hole with a square cross-section into which it is inserted. 4 and 5, the lever 40 is supported by the base structure 16 and is
Cooperates with an adjustment mechanism 42 that can change the angular position of. In the embodiment illustrated in FIGS. 4 and 5, the adjustment mechanism 42 includes a vertically slidable wedge 44 on a guide wall 46 of the substructure 16. The wedge 44 is connected to the lever 40
A shoe 50 having a concave sheet 52 that supports a rounded end 54 (see FIG. 7) has an inclined guide surface 48 slidably mounted along it. The wedge 44 can be moved longitudinally by turning a knob 56 located outside the foundation 16 in the central portion of the front of the chair. The knob 56 is rotatably connected to a threaded rod 58 that is axially mounted to the substructure 16 and is free to rotate about its own longitudinal axis. Bar 58 with screw
Engages a threaded nut 60 attached to wedge 44. The elastic action of the torsion spring 32 has a characteristic of keeping the lever 40 pressed against the shoe 50. Thus, the movement of the wedge 44, which can be manually controlled by the user through the knob 56, changes the angular position of the lever 40, which in turn changes the angular position of the central section 32b of the torsion spring with respect to its own axis. .

FIGS. 4 and 5 illustrate two end-of-travel positions of the wedge 44 that define an adjustment field for the mechanism 42. Each angular position of lever 40 corresponds to a particular amount of preload on torsion spring 32. Because the seat support structure 14 is attached to the end of the torsion bar 32, the preload of the torsion bar 32 opposes the skew of the seat in the direction indicated by arrow 62 in FIGS.
Therefore, the user has the possibility to continuously adjust the elastic force against the tilting operation of the sheet between the minimum value and the maximum value.
From the above description, it will be appreciated that the torsion bar 32 performs both the function of an elastic member to counteract the tilting movement of the seat and back, and the function of a pivot member between the seat support structure 14 and the base structure 16. Like.
This arrangement makes the tilting mechanism for the seat particularly small in that the space required to house the shaft, which usually provides the seam between the seat support structure and the substructure, also incorporates elastic members. The adjustment mechanism 42 allows a significant reduction in operating force to be achieved, so that the knob 56 can be easily operated without having to apply excessive force.

FIGS. 8 and 9 illustrate a variant of the adjusting mechanism according to the invention. Details corresponding to those previously described are indicated by the same reference numerals. In this variation, the threaded rod 58 is replaced by a shaft 64 having at one end a profile 66 that can rotate with the threaded rod 70 and engage a wheel 68 incorporated therewith. The threaded rod 70 is free to rotate about its own longitudinal axis and engages a nut 72. The lever 40 mounted on the central section 32b of the torsion bar 32 has a fork-shaped end with two rims 74 supporting nuts 72 opposite the threaded bar 70. The resilient reaction force of the torsion bar 32 exerts a downward force on the nut 72, preventing the latter from rotating about the axis of the threaded rod 70. Thus, rotation of the shaft 64, controlled by the manually operated knob 56 (not seen in FIGS. 8 and 9), can be used to move the nut 72 up and down, and consequently the angular position of the lever 40. Can be used to vary. Also in this case, the user can change the elastic force opposing the fluctuation operation of the seat from the minimum value to the maximum value by rotating the knob 56.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a chair according to the present invention.

FIG. 2 is a bird's-eye view of a mechanism for tilting the seat of the chair of FIG. 1;

FIG. 3 is a plan view taken along an arrow III of FIG. 2;

FIG. 4 is a cross section taken along line IV-IV in FIG. 3;

FIG. 5 is a cross section taken along line IV-IV in FIG. 3; The operation position is different from that of FIG.

FIG. 6 is a partial cross section taken along line VI-VI of FIG. 3;

FIG. 7 is a cross section taken along line VII-VII of FIG. 4;

FIG. 8 is a cross section similar to the cross section in FIGS. 4 and 5, illustrating a variation of the present invention.

FIG. 9 is a schematic cross section taken along line IX-IX of FIG. 8;

[Explanation of symbols]

 14 Seat support structure 16 Foundation structure 24 Transverse tilt axis 32 Torsion bar (elastic means) 40 Lever 44 Wedge 56 Knob

Claims (5)

[Claims] 1. A base structure (16) for supporting a cross-tilt axis (24), a seat support structure 14 capable of tilting around the cross-tilt axis (24), and capable of opposing a seat tilting operation. A chair provided with a tilting seat, comprising a resilient means (32) and an adjusting means (42) for changing the force opposing the resilient means (32), wherein the resilient means comprises a seat support structure (14). In a manner inclined to the periphery of the transverse oblique axis (24).
A torsion bar (32) connected to at least one first portion (32a) rotatably connected to the seat support structure (14), and the base structure (16) by the adjusting means. C) having at least one second part (32b) connected to the chair. 2. The adjusting means (42) for changing the angular position of the second portion (32b) of the torsion spring (32) with respect to the transverse oblique axis (24). The chair according to 1. 3. The adjusting means (42) comprises a lever (40) mounted on the second portion (32b) of the torsion bar (32), a manually operated rotary knob (56), and an angular position of the knob (56). Chair according to claim 2, characterized in that it comprises a restraining device defining the correlation between the position and the angular position of the lever (40). 4. The control device according to claim 1, wherein the control device includes a lever.
0) with one end (54) of the inclined surface (4).
8) having a longitudinally slidable wedge (44) having a screw and nut capable of changing the axial position of the wedge (44) with respect to the angular position of the operating knob (56). Working with the mechanism (58, 60),
The chair according to claim 3, characterized in that: 5. The restraining device has a pair of tooth wheels (66, 68) that mesh together, the first tooth wheel (66) being rotatably connected to an operating knob (56),
The second toothed wheel (68) is connected to the lever (4
4. A chair according to claim 3, characterized in that it is incorporated in and rotates with a threaded rod (60) engaging a nut (72) acting with one end of 0).